Joseph bedford



UNrTE PATENT OFFICE.

Josnrn nnoronn, or SHEFFIELD, ENGLAND.

SPECIFICATION forming part of Letters Patent N 0. 477,490, dated June21, 1892. Application filed November 25, 1891. Serial No. 413,092. (Nospecimens.) Patented in England December 13, 1887, No. 17,156.

To all whom it may concern.-

Be it known that I, JOSEPH BEDFORD, a subject of the Queen of GreatBritain and Ireland, residing at Sheffield, in the county of York,England, have invented a certain new and Improved Method of PurifyingAlloys of Iron and Chromium, (for which I have reeeived Letters Patentin Great Britain, No. 17,156, dated December 13, 1887;) and I do herebydeclare that the following is a full, clear, and exact description ofthe invention, which will enable others skilled in the art to which itappertains to make and use the same.

My invention relates especially to the treat ment and purification ofalloys of iron and chromium, containing also carbon, silicon, sulphur,phosphorus, and manganese, and which alloys are ordinarily known incommerce as chrome pig'ironfl chromeisen, or ferro-chromi um.

I am aware that prior to my invention certain processes existed for thepurification of pig-iron and mixtures of pig-iron with scrapiron orscrap-steel-as, for instance, those of Bessemer, Siemens, Thomas, andGilchrist, and others; but it is not with such material that I proposeto deal nor to which my invention has reference,

My object is to purify the crude alloys of chromium and iron fromsilicon, sulphur, phosphorus, and manganese as completely as possibleand to eliminate the whole or any portion of the carbon, so as to renderthem suitable, say, for producing a steel superior to that made by theuse of the crude alloys of chromium and iron now met with in commerce. Ican effect this purification either in a separate operation or in anoperation preliminary to or constituting part of the process ofmanufacturing chrome steel with such purified alloy, or in an operationin which such purified alloy is produced in a separate or subsidiaryfurnace, from which it may be poured in a molten state at thecommencement of or at any subsequent stage of the steel-manufacturingprocess; or I may add the solid purified alloy at any stage of thesteel-manufacturing process, in the manner hereinafter described. I can,also, by the addition to such purified alloy (in the manner hereinafterspecified) of tungsten, copper, nickel, aluminium, manganese, silicon,or phosphorus, or any combinations of them, render these purified alloyssuitable for use in the manufacture of steel or for the manufacture ofbrass, gun-metal, bronze, anti-friction metal, or similar alloys of ironor metals other than iron, as largely used in the arts.

In carrying out my invention I proceed in the following manner: On thehearth or bed of an open hearth, or other suitable furnace, (preferablylined with basic material, as now well known in steel-manufacturingprocesses, or lined with chrome ore or ganister or other suitable material,) I place a charge of hematiteiron ore, manganese ore, ormanganiferousiron ore, and chrome ore, whether containing iron or not;or I introduce quieklime or magnesian lime, or other suitable alkaline,alkaline-earthy, or earthy substance. In using the word ore 7 abovemyintention is to cover the use of any minerals,whether oxides,sulphides, carbonates, chlorides, or other compounds. Upon such bed of Iores I charge a properlyproportioned weight of the crude alloy here:inbefore stated, together with either or any of the materials charged atthe outset, as just mentioned. The whole is then melted, with or withoutstirring, and when sufficiently melt-ed or prepared a further charge ofextra material can, if desired, be added. The re sulting product of thisoperation is the purified alloy, free, or nearly so, from silicon,sulphur, phosphorus, and manganese and with a reduced percentage ofcarbon. This purified product may be either run out into suitable moldsfor future use or be added in amolten state to a charge of steel inanother furnace, or may be used to form the preliminary melting or basisin the same or another furnace for a charge of pig-iron, steel, or ironscrap or other materials commonly used in the manufacture of steel. Theprocess of steel manufacture is conducted in the ordinary manner, thepurified alloy being added at the outset or at any subsequent stage andin either the molten or the solid state. a At the later stages or at theend the usual additions of ferromanganese or spiegeleisen may be made;or aluminium maybe used instead for the decomposition and elimination ofthe contained gases.

When it is required to incorporate or combine with such purified chromealloy tungsten, copper, nickel, aluminium, silicon, or phosphorus, orany one or any combination of these for the purpose of producing acompound alloy, I add to the alloy, at any stage or at the end of thepurifying process and in any desired proportion, any one or more of thefollowing substances: For producing a compound alloy containing tungstenI add metal- 110 tungsten or any alloy thereof. For producing a compoundalloy containing copperI add metallic copper or any alloy thereof. Forproducing a compound alloy containing nickel I add metallic nickel orany alloy thereof. For producing a compound alloy containing aluminiumIadd metallic aluminium or any alloy thereof. For producinga compoundalloy containing manganese I add metallic manganese or any alloythereof, as term-manganese, spiegeleisen, iron-nickel-manganese alloy,or alloy of manganese with any other metal. For producing acompoundalloy containing silicon I add ferro-silicon,silicious pig-iron,or silicospiegel, or silicide of iron and manganese. For producing acompound alloy containing phosphorus I add phosphorus or any phosphide,either a phosphide of a metal or of a non-metal.

The alloys so made, containing one or more of the ingredients abovespecified in combination with iron and chromium, possess many valuableproperties and combine great strength with toughness, which render themsuitable for the manufacture of iron, steel, brass, bronze, gun-metal,anti-friction metal, and for many other well-known purposes.

I do not confine myself to any exact percentages of chromium or carbonwhich my purified alloy is to contain, as these may be varied to suitcircumstances; but I give, as an example: chromium, twelve per cent;carbon, 0.25 per cent; manganese, 0.2 per cent; silicon, 0.01 per cent;phosphorus, 0.02 per cent, and sulphur 0.02 per cent; but I may makethis alloy to contain from one to fifty per cent. or upward of chromium,from none to two per cent. or more carbon, keeping the other ingredientsas low as possible, and adding, if I wish, any desired proportion of anyother element, as tungsten, copper, nickel, aluminiumnnan ganese,silicon ,or phosphorus.

Steel alloyed with chromium according to this invention is much tougherand more ductile than that made by the processes now in use, and is verymuch better suited for materials requiring high tensile strain, such aswire or steel for railway purposes, or for materials required to resistimpact, such as projectiles or armor-plates, or for materials requiredto resist compression, such as for ordnance purposes, for ship-plates,and for engineers purposes, such as dies and stamps, and in allstructural work, as for girders and bridges.

Having f ully described my invention, what I claim, and desire to secureby Letters Patent, is

1. The herein-described method of purifying alloys of iron and chromiumcontaining carbon and other metalloids and manganese, which consists inmelting such alloys with ore in a suitably-lined furnace, so as todissociate the carbon and other metalloids and manganese contained inthe alloys, thereby producing a pure alloy of iron andchromium.

2. The herein-described method of purifying alloys of iron and chromiumcontaining carbon and other metalloids and manganese, which consists inmelting such alloys with ore in a furnace lined with basic material, soas to dissociate the carbon and other metalloids and manganese containedin the alloys, thereby producing a pure alloy of iron and chromium.

3. The herein-described method of purifying alloys of iron and chromiumcontaining carbon and other metalloids and manganese, which consists inmelting suchalloys with ores of iron in a furnace lined with basicmaterial, so as to dissociate the carbon and other metalloids andmanganese contained in the alloys, thereby producing a pure alloy ofiron and chromium.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

JOSEPH BEDFORD.

Witnesses:

CHARLES 13. LAISTOE, FRANK M. CLARK.

